Make a collection of audio files featuring the extracted Leia Hologram speech that contains parts of the speech that are clean and parts where there is still music leakage. These groups of audio files would be made up from several music mixes from either the CD or film, whether it be just the left channel, just the right channel, the sum of the left and the right, just the rear channel, the sum of the left, right, and rear, etc. You are basically throwing every music mix in any combination and seeing how much clean parts you can get.
Hopefully each extracted audio file will have clean parts of the dialog but not in the same places. Go to each audio file, select the clean parts, put them all in a separate blank audio file and edit them together into one clean audio file.
If after you do all that and you still have portions of the speech with music leakage, then listen to each portion and see what music instrument(s) is heard predominantly. Make up a music mix where that instrument is heard at that high level or try EQing.